Coupled bioconversion for preparation of N-acetyl-d-neuraminic acid using immobilized N-acetyl-d-glucosamine-2-epimerase and N-acetyl-d-neuraminic acid lyase

摘要: N-Acetyl-d-neuraminic acid (Neu5Ac) can be produced from N-acetyl-d-glucosamine (GlcNAc) and pyruvate by a chemoenzymatic process in which an alkaline-catalyzed epimerization transforms GlcNAc to N-acetyl-d-manosamine (ManNAc). ManNAc is then condensed biocatalytically with the presence of N-acetyl-d-neuraminic lyase (NAL) or two-step, fully enzymatic involving bioconversions Neu5Ac using 2-epimerase (AGE) NAL. There are some drawbacks this technique, such as lengthy reaction time, low conversion rate when soluble forms enzymes used two-step process. In study, Escherichia coli-expressed AGE NAL supernatant were purified FP-based affinity chromatography immobilized on Amberzyme oxirane resin. These two enzymes, specific activity 78.18 U/g for 69.30 NAL, coupled convert directly one reactor. The reactions was ∼73% within 24 h. Furthermore, could both up five cycles without loss significant decrease rate.